/*
 * This program is free software: you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by the Free Software
 * Foundation, either version 3 of the License, or (at your option) any later
 * version.
 * 
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
 * details.
 * 
 * You should have received a copy of the GNU General Public License along with
 * this program. If not, see <http://www.gnu.org/licenses/>.
 */
package com.l2jserver;

import java.sql.Connection;
import java.sql.SQLException;
import java.util.logging.Level;
import java.util.logging.Logger;

import com.l2jserver.gameserver.ThreadPoolManager;
import com.mchange.v2.c3p0.ComboPooledDataSource;

public class L2DatabaseFactory
{
	static Logger _log = Logger.getLogger(L2DatabaseFactory.class.getName());
	
	public static enum ProviderType
	{
		MySql, MsSql
	}
	
	// =========================================================
	// Data Field
	private static L2DatabaseFactory _instance;
	private ProviderType _providerType;
	private ComboPooledDataSource _source;
	
	//	private ComboPooledDataSource _source2;
	// =========================================================
	// Constructor
	public L2DatabaseFactory() throws SQLException
	{
		try
		{
			if (Config.DATABASE_MAX_CONNECTIONS < 2)
			{
				Config.DATABASE_MAX_CONNECTIONS = 2;
				_log.warning("A minimum of " + Config.DATABASE_MAX_CONNECTIONS + " db connections are required.");
			}
			
			_source = new ComboPooledDataSource();
			_source.setAutoCommitOnClose(true);
			
			_source.setInitialPoolSize(10);
			_source.setMinPoolSize(10);
			_source.setMaxPoolSize(Math.max(10, Config.DATABASE_MAX_CONNECTIONS));
			
			_source.setAcquireRetryAttempts(0); // try to obtain connections indefinitely (0 = never quit)
			_source.setAcquireRetryDelay(500); // 500 milliseconds wait before try to acquire connection again
			_source.setCheckoutTimeout(0); // 0 = wait indefinitely for new connection
			// if pool is exhausted
			_source.setAcquireIncrement(5); // if pool is exhausted, get 5 more connections at a time
			// cause there is a "long" delay on acquire connection
			// so taking more than one connection at once will make connection pooling
			// more effective.
			
			// this "connection_test_table" is automatically created if not already there
			_source.setAutomaticTestTable("connection_test_table");
			_source.setTestConnectionOnCheckin(false);
			
			// testing OnCheckin used with IdleConnectionTestPeriod is faster than  testing on checkout
			
			_source.setIdleConnectionTestPeriod(3600); // test idle connection every 60 sec
			_source.setMaxIdleTime(Config.DATABASE_MAX_IDLE_TIME); // 0 = idle connections never expire
			// *THANKS* to connection testing configured above
			// but I prefer to disconnect all connections not used
			// for more than 1 hour
			
			// enables statement caching,  there is a "semi-bug" in c3p0 0.9.0 but in 0.9.0.2 and later it's fixed
			_source.setMaxStatementsPerConnection(100);
			
			_source.setBreakAfterAcquireFailure(false); // never fail if any way possible
			// setting this to true will make
			// c3p0 "crash" and refuse to work
			// till restart thus making acquire
			// errors "FATAL" ... we don't want that
			// it should be possible to recover
			_source.setDriverClass(Config.DATABASE_DRIVER);
			_source.setJdbcUrl(Config.DATABASE_URL);
			_source.setUser(Config.DATABASE_LOGIN);
			_source.setPassword(Config.DATABASE_PASSWORD);
			
			/* Test the connection */
			_source.getConnection().close();
			
			/*			_source2 = new ComboPooledDataSource();
						_source2.setAutoCommitOnClose(true);
						
						_source2.setInitialPoolSize(10);
						_source2.setMinPoolSize(10);
						_source2.setMaxPoolSize(Math.max(10, Config.DATABASE_MAX_CONNECTIONS));
						
						_source2.setAcquireRetryAttempts(0); // try to obtain connections indefinitely (0 = never quit)
						_source2.setAcquireRetryDelay(500); // 500 milliseconds wait before try to acquire connection again
						_source2.setCheckoutTimeout(0); // 0 = wait indefinitely for new connection
						// if pool is exhausted
						_source2.setAcquireIncrement(5); // if pool is exhausted, get 5 more connections at a time
						// cause there is a "long" delay on acquire connection
						// so taking more than one connection at once will make connection pooling
						// more effective.
						
						// this "connection_test_table" is automatically created if not already there
						_source2.setAutomaticTestTable("connection_test_table");
						_source2.setTestConnectionOnCheckin(false);
						
						// testing OnCheckin used with IdleConnectionTestPeriod is faster than  testing on checkout
						
						_source2.setIdleConnectionTestPeriod(3600); // test idle connection every 60 sec
						_source2.setMaxIdleTime(Config.DATABASE_MAX_IDLE_TIME); // 0 = idle connections never expire
						// *THANKS* to connection testing configured above
						// but I prefer to disconnect all connections not used
						// for more than 1 hour
						
						// enables statement caching,  there is a "semi-bug" in c3p0 0.9.0 but in 0.9.0.2 and later it's fixed
						_source2.setMaxStatementsPerConnection(100);
						
						_source2.setBreakAfterAcquireFailure(false); // never fail if any way possible
						// setting this to true will make
						// c3p0 "crash" and refuse to work
						// till restart thus making acquire
						// errors "FATAL" ... we don't want that
						// it should be possible to recover
						_source2.setDriverClass(Config.DATABASE_DRIVER);
						_source2.setJdbcUrl("jdbc:mysql://79.98.27.133/l2lb_users");
						_source2.setUser("l2lb_users");
						_source2.setPassword("123456");
						
						 Test the connection 
						_source2.getConnection().close();*/

			if (Config.DEBUG)
				_log.fine("Database Connection Working");
			
			if (Config.DATABASE_DRIVER.toLowerCase().contains("microsoft"))
				_providerType = ProviderType.MsSql;
			else
				_providerType = ProviderType.MySql;
		}
		catch (SQLException x)
		{
			if (Config.DEBUG)
				_log.fine("Database Connection FAILED");
			// re-throw the exception
			throw x;
		}
		catch (Exception e)
		{
			if (Config.DEBUG)
				_log.fine("Database Connection FAILED");
			throw new SQLException("could not init DB connection:" + e);
		}
	}
	
	// =========================================================
	// Method - Public
	public final String prepQuerySelect(String[] fields, String tableName, String whereClause, boolean returnOnlyTopRecord)
	{
		String msSqlTop1 = "";
		String mySqlTop1 = "";
		if (returnOnlyTopRecord)
		{
			if (getProviderType() == ProviderType.MsSql)
				msSqlTop1 = " Top 1 ";
			if (getProviderType() == ProviderType.MySql)
				mySqlTop1 = " Limit 1 ";
		}
		String query = "SELECT " + msSqlTop1 + safetyString(fields) + " FROM " + tableName + " WHERE " + whereClause + mySqlTop1;
		return query;
	}
	
	public void shutdown()
	{
		try
		{
			_source.close();
			//			_source2.close();
		}
		catch (Exception e)
		{
			_log.log(Level.INFO, "", e);
		}
		try
		{
			_source = null;
			//			_source2 = null;
		}
		catch (Exception e)
		{
			_log.log(Level.INFO, "", e);
		}
	}
	
	public final String safetyString(String... whatToCheck)
	{
		// NOTE: Use brace as a safty precaution just incase name is a reserved word
		final char braceLeft;
		final char braceRight;
		
		if (getProviderType() == ProviderType.MsSql)
		{
			braceLeft = '[';
			braceRight = ']';
		}
		else
		{
			braceLeft = '`';
			braceRight = '`';
		}
		
		int length = 0;
		
		for (String word : whatToCheck)
		{
			length += word.length() + 4;
		}
		
		final StringBuilder sbResult = new StringBuilder(length);
		
		for (String word : whatToCheck)
		{
			if (sbResult.length() > 0)
			{
				sbResult.append(", ");
			}
			
			sbResult.append(braceLeft);
			sbResult.append(word);
			sbResult.append(braceRight);
		}
		
		return sbResult.toString();
	}
	
	// =========================================================
	// Property - Public
	public static L2DatabaseFactory getInstance() throws SQLException
	{
		synchronized (L2DatabaseFactory.class)
		{
			if (_instance == null)
			{
				_instance = new L2DatabaseFactory();
			}
		}
		return _instance;
	}
	
	public Connection getConnection() //throws SQLException
	{
		Connection con = null;
		
		while (con == null)
		{
			try
			{
				con = _source.getConnection();
				if (Config.DEBUG)
					ThreadPoolManager.getInstance().scheduleGeneral(new ConnectionCloser(con, new RuntimeException()), 40000);
			}
			catch (SQLException e)
			{
				_log.warning("L2DatabaseFactory: getConnection() failed, trying again " + e);
			}
		}
		return con;
	}
	
	/*	public Connection getConnection2() //throws SQLException
		{
			Connection con = null;
			
			while (con == null)
			{
				try
				{
					con = _source2.getConnection();
					if (Config.DEBUG)
						ThreadPoolManager.getInstance().scheduleGeneral(new ConnectionCloser(con, new RuntimeException()), 40000);
				}
				catch (SQLException e)
				{
					_log.warning("L2DatabaseFactory: getConnection() failed, trying again " + e);
				}
			}
			return con;
		}*/

	private class ConnectionCloser implements Runnable
	{
		private Connection c;
		private RuntimeException exp;
		
		public ConnectionCloser(Connection con, RuntimeException e)
		{
			c = con;
			exp = e;
		}
		
		/* (non-Javadoc)
		 * @see java.lang.Runnable#run()
		 */
		@Override
		public void run()
		{
			try
			{
				if (!c.isClosed())
				{
					_log.warning("Unclosed connection! Trace:");
					exp.printStackTrace();
				}
			}
			catch (SQLException e)
			{
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
			
		}
	}
	
	public int getBusyConnectionCount() throws SQLException
	{
		return _source.getNumBusyConnectionsDefaultUser();
	}
	
	public int getIdleConnectionCount() throws SQLException
	{
		return _source.getNumIdleConnectionsDefaultUser();
	}
	
	public final ProviderType getProviderType()
	{
		return _providerType;
	}
}
